Bearing.



, always be a ver UNITED STATES PATENT OFFICE.

JOHN RIDDELL, OF SOHENECTADY, NEW YORK, ASSIGNOB TO Gm ELECTRIC COMPANY,A. CORPORATION OF NEW YORK.

Patented Mar. 21, 1916.

BEARING.

1,176,603, Specification of Letters Patent. No Drawing. Applicationflied October 20, 1918. Serial No. 796,838.

To all whom it may concern:

Be it known that I, J 01m Execute, a citizen of the United States,residing at Schenectady, in the county of Schenectady, State of NewYork, have invented certain new and useful Improvements in Bearings, ofwhich the following is a specification.

My invention relates to bearings and bearing surfaces, and its object isto provide metallic hearings or bearing surfaces of superior running andwearing qualities and of relatively low cost.

The invention is applicable to shafts; to journal boxes, to cylinderspistons, and iston rings of internal com ustion or ot er en ines' and tothe wearing surfaces of other re atively movable parts.

Various advantages besides those already mentioned that can be realizedin connection with my invention will hereinafter become apparent, andits scope will be indicated in m claims.

In accor ance with my invention, bearin arts of metallic materialswhich, thoug 1n some respects suitable or desirable for bearings, areotherwise either initially or permanently more or less unsatisfactoryfor the purpose, are rendered entirely satisfactory or greatly improvedby a surface stratum in which other metallic material is intimatelyincorporated. This incorporation of other material at the bearingsurface may even indeed, be such that the initially exposed surfaceshall be that of an appreciably thick layer or stratum consisting whollyof such other material; but whether this is so or not, the union betweenthe metal of the bearing part as a whole and that superficiallyincorporated with'it must intimate one. I am at present of theOPlIllOl'i that this intimacy of union can only be obtained whenalloying is caused to occur between the superficially added metal andthat of the bearing part itself,so that when there is a distinct surfacelayeror stratum of such metal the same will be as it were, anchored orbonded to the underlying metal of the bearing parts by a sub-stratum ofsome sort of alloy,-the term alloy being here used in its inclusiveopular sense of an intimate union of diferent metals such as can in manycases be produced b heat, rather than in any strict and limite technicalsense. Such coatings as can at present be produced by electroplatingmethods are entirely unsuitable for the purposes of m invention byreason of their sponginess, t eir insuflicient adhesion to theunderlying metal, etc.

In partic ar, bearing arts of various sorts of ferrous metal canmateriall improved by means of my invention. oreo ver, I have found thatpeculiar and especially advantageous results can be obtained by coatingthe bearing surfaces of cast iron journal boxes or bearings for steelshafts with zinc when the coating is eflected by heating the bearings toa suitable tem erature in contact with very finely divide zinc or zincdust; and as a sherardized gray cast ron bearin for a steel shaftexhibits the important eatures and advanta es of my invention veryclearly, I will hereinafter describe in detail, the preparation of sucha bearing.

Assuming that bearings for a motor shaft of, say, 2} to 3'. diameter areto be made 1n accordance with my invention, gra iron castings such aswould be used for or 'nary cast iron bearings intended to be run withoutbabbitt or other special metal bearing surfaces are roughly bored orreamed out and are then annealed at about a bright red heat. The objectof this annealing is to insure against distortion in the subsequent heattreatment by which the zinc is applied.

After annealing, the interior of the bearing is finally reamed andfinished as usual for cast iron bearin but about 5/1000 of an inchlarger in diameter than the shafts for which t ey are intended. Thesebearin are then heated in zinc dust in a tight y closed revolving box orcylinder at about the dull red heat of iron or somewhat hi her for fromthree to four hours or more. sherardizing treatment may be carried outin any ty e of furnace in which a uniform heat of this term erature canbe maintained, as, for examp e, in that shown in U. S. Patent 1,034,930anted to me Au st 6th, 1912. At the on of the heating, t e cylinder orbox is allowed to cool to about 200 C. before bein opened, to preventthe zinc dust from oatc ing fire. The bearings may then be reamed outagain with'a full size reamer,although this is not strictly necessary,especially with relatively small bear- The resultof the proceduredescribed will 11! be to coat with zinc the exterior of the hearing aswell as its hearing or running surface proper, especially if theexterior has previously been well cleaned by sand blasting, pickling, orthe like. This complete coating offers the advantage of protecting theexterior of the bearing from rust under all conditions, and it is alsopractically easier and cheaper than coating only a part of the surface';but if for any reason it is desired that some part of the surface (suchas a ball seat) should not be coated, this can be avoided by theapplication thereto prior to the sherardizing of fire clay worked upwith a little water.

The sherardizing operation should be so carried out that the coatingformed on the interior or running surface of the bearing will be fromtwo to two and one-half thousandths of an inch thick, or over. Ifcircumstances re uire it, the temperature or the duration of t e heattreatment should be made greater or less so that a coating of about thisthickness will still be obtained; in dealin with large bearing parts, inparticular, the temperature or duration of the heating may need to beincreased. For the best results as regards the behavior of the bearingsin service, the procedure should be so conducted (having regard to thearticular zinc dust employed, etc.) that t e coating will be firm,close, and dense rather than loose or orous.

The s erardized bearing surface appears to comprise an outer layer orstratum of zinc anchored to the cast iron beneath by an intermediatestratum comprising alloyed zinc and iron, this latter stratum consistingpartly of zinc alloyed with iron (toward the outside) and partly of ironpenetrated and alloyed with zinc (deetper m),--the enetration andalloyin o the iron wit the zinc being facilitated by the porosity of theiron. At any rate, the union between the zinc surface and theironbeneath a very firm and intimate one, so that the bearing possesses in ahigh de all the qualities that I have indicated .a ove as requisite forsecurin the advantages of my invention. The zinc coat will probablyalways contain zinc oxid from the zinc dust used in producing it; but ifthe sherardizin conditions have been such as to ield a goo coating ofthe character herein efore described, this will do no harm.

In use, the sherardized bearing will be found entirely free from many orall of the objections to which ordinary cast iron bearings areinitiallly subject,--such as excessive friction, a ten ency to heat orscore, and the necessit for profuse lubrication. The cost of sue abearin is, moreover, very low in comparison wit bronze, babbltt, orother similar bearin The zinc coating produced as descri is perfectlyuniform and free from globules, ridges or unevennesses of any sort, sothat it requires no real finishing; the coeflicient of friction betweenthe sherardized surface and an ordinary steel shaft is perfectlysatisfactory; the bearing is adapted for hi her runnin speeds; and thewearing qualities are excel ent. Scratching and scoring of either theshaft or the hearingor journal-such as is liable to occur with a newplain cast iron surface-are effectually prevented throughout the life ofthe bearing. This may be due to one or both of the causes: either thatafter the initial bearing surface consisting entirely of zinc is wornaway the loose particles of iron and of carbon which the surfaces ofcast iron bearings always resent when newly finished are still held astby the zinc (or some alloy thereof with the iron) which fills the poresof the latter; or else that the loose iron and carbon particles near thesurface may res ectively be eliminated by alloying and di usion into thezinc and by reaction with the zinc oxid present in the zinc dust.However this may be, I find that by the time the bearing is worn down tothe plain cast iron the latter will have the well worn and polishedsurface that is characteristic of a cast iron bearing after its initialcritical period is past, so that the final disappearance of the zincwill not im air the bearings initial good qualities in t e least.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. A bearing of ferrous metal havin its bearing surface im roved b supercial incorporation and a oying 0 other metal thereinto.

2. A hearing of porous metal having its bearing surface improved and thepores therein filled by superficial incorporation and alloying of othermetal in said surface.

3. A bearing of metal having its bearing surface improved b superficialincorporation and a loyin o zinc thereinto.

4. As an artic e of manufacture, a bearing of ferrous metal having onits bearing surface a thin coatin of zinc anchored in place by alloyinwit the ferrous metal.

5. As an artic e of manufacture, a hearing of ferrous metal having onits bearing surface a coating of other metal formed in situ and anchoredin lace by alloying with the ferrous metal, said coatin being so thin asto wear away completely uring the useful life of the bearing.

6. A hearing of cast iron havin its hearing surface improved superficiaalloying and incorporation thereinto of an amount of zinc such as towear away and disa pear completely during the useful life 0 the bearing.

7. As an article of manufacture, a hearing of gray cast iron having onits bearing surface a coating of other metal anchored in place ofalloying with the iron and so thin In witness whereof, I have hereuntoset as to wear awa completely during the usemy hand this 18th day ofOctober, 1913. 111 of eating. 8. A bearing of ferrous metal having a 5sherardized bearing surface. Witnesses:

9. A bearing of gray cast ironhaving :1 ROBERT Rum, sherardizing bearingsurface. T Hmmz Onroxm.

place 'of alloying with the iron and so thin as to wear awa completelyduring the useful life of the earing.

8. A bearing of ferrous metal having a In witness whereof, I havehereunto set my hand this 18th day of October, 1913.

' JOHN RIDDELL.

sherardized bearing surface. Witnesses:

9. A hearing of gray cast iron having'a ROBERT REID, sherardizlngbearing surface. HELEN ORFORD.

Corrections In Letters Patent Ne."1,176,603.'

' It is hereby certified that in: Letters Pawn No.'i,176,eo3,granted-Mamba, 1916', lipon the application of John Riddelh ofSchenectady, New York, for animprovement in Bearings, errors appear inthe printed specification'requiring correction as followsz Iage 2,line.-' 78, for theword the, first occnrrence, read two; same page, line123, claim 6 for the-word in, readlb y; same page, line 129,

claim 7, and page 3, line 6, claim 9, tor the word gray read grey; page3, line 1,

claim 7, for the word of i read by; same page, linef'7, claim 9, for theword ,sherardiziing read sherdfd'ized; and that the said IiettersyPatent be read with these corrections therein thatthe same mayconform to the record of the case in .thePatentQflice. I

. Signed and sealed this 27th day of June, A.'D., 1916. a a y [SEAL-1 Ih Y ActiagGommi'aeioagi-bflm.

It is hereby certified that in Letters Patent No. 1,176,603, grantedMarch 21,

1916, npon the application of John Riddell, of Schenectady, New York,for an improvement in Bearings, errors appear in the printedspecification requiring correction as follows: Page 2, line '78, for theword the, first occurrence, read two; same page, line 123, claim 6, forthe word in, read by; same page, line 129, claim 7, and page 3, line 6,claim 9, for the word "gray read grey; page 3, line 1,

claim 7, for the word "of read by; same page, line 7, claim 9, for theword sherardizfing read shemrd'ized; and that the said I letters Patentshould be read with these corrections therein that the game may conformto the record of the case in the Patent Oflice.

. Signed and sealed this 27th day of June, A. 1)., 1916.

R. F. WHITEHEAD,

Acting of PM.

. [BELL]

